The function of a suspension system with an oscillating axle is to allow for travel over irregular ground surfaces. However, in the case of vehicles such as those with a lift or rotating extensible boom, an oscillating axle has been a disadvantage for maximizing stability when the vehicle is stationary and the lift or boom are in operation. The object of the present invention is to provide an oscillating axle system in which there is a solid connection between the oscillating axle and the chassis when needed to maximize stability, and which also permits oscillation during driving of the associated vehicle without loss of stability.